The present invention relates in general to an adsorption filter material that is suitable for the production of protective materials of any kind, such as protective suits, protective gloves, protective footwear and other protective garments and also protective covers (for example to transport casualties), sleeping bags and the like, not only for the military sector but also for the civilian sector, especially for NBC deployment.
There are a whole series of chemical noxiants which are absorbed by the skin and lead to serious physical harm. Examples include the vesicatory mustard agent (Yellow Cross) and the nerve agent sarin. People likely to come into contact with such poisons must wear suitable protective apparel or be protected against these poisons by suitable protective materials.
Protective materials known for this purpose include for example air and water vapor impervious protective suits which are equipped with a layer of rubber impervious to chemical poisons. The disadvantage here is that these suits very rapidly lead to a heat buildup, since they are air and water vapor impervious.
Protective suits against chemical warfare agents that are intended for prolonged use under a wide variety of conditions, however, must not lead to heat buildup for the wearer. Air and water pervious protective suits are known for this purpose because they offer the highest wear comfort.
The air pervious, permeable protective suits generally possess an absorption filter layer based on activated carbon which binds the chemical poisons very durably, so that even badly contaminated suits cannot pose any danger to the wearer. The great advantage of such systems is that the activated carbon is accessible on the inside as well as the outside, so that poisons which have succeeded in penetrating at damaged or otherwise non-tight locations can be very rapidly adsorbed.
The adsorbing layer in the air pervious, permeable protective suits described above can in this case be engineered such that for example either activated carbon particles up to about 1.0 mm in size on average, especially granules or spherules of activated carbon, are bonded to a small heap of adhesive printed onto a textile carrier material, or else a reticulated polyurethane foam impregnated with a “carbon paste” (i.e., binder plus activated carbon) is used as an adsorbing layer, in which case the adsorbing layer is generally complemented by an outer, i.e., covering material, and the wearer-facing inside surface is covered by a lightweight textile material.
But there are also assemblage materials comprising an activated carbon fiber fabric, for example a woven or a nonwoven batt fabric of activated carbon fiber.
For instance, WO 94/01198 A1, entitled “Mutilayered, Gas-Permeable Textile Filtering Material Against Toxic Chemical Substances”, by inventors Stelzmüller et al, published Jan. 20, 1994, or its equivalent EP 0 649 332 B1, issued Apr. 17, 1996, describes a multi-ply textile adsorption filter material against harmful chemicals, which comprises two outer textile carrier layers and an interposed woven activated carbon fiber fabric which is uniformly adhered to the two outer layers in order that adequate mechanical stability may be ensured for the woven activated carbon fiber fabric even under extreme mechanical stress of the kind encountered in the wearing of protective suits for example. Disadvantages here are the large amount of adhesive needed for the uniform adhesive bond and the consequently elevated basis weight of the resulting adsorption filter material, and also the stiffness due to the uniform adhesive bond. A particular disadvantage is the air imperviousness which results from the uniform adhering of the woven activated carbon fiber fabric to the two textile outer layers and which, according to WO 94/01198 A1 or EP 0 649 332 B1, has to be compensated by having to introduce small perforations into the uniform add-on of adhesive.
EP 0 230 097 A2, entitled “Needled Layered Material Containing Activated Carbon Fibres”, by inventor Keith Simpson, published Jul. 29, 1987, Bulletin 87/31, describes the failed attempt to produce a stable assemblage material in the form of a laminate from two outer textile plies and an interposed layer of woven activated carbon fiber fabric adhered to the two outer plies. The materials produced in this way are incapable of withstanding any mechanical stress and the woven activated carbon fiber fabric disintegrates into a fine dust when exposed to mechanical stress (cf. EP 0 230 097 A2 page 1 line 25 to page 2 line 8).
The present invention is directed to providing an adsorption filter or protective material which may substantially or completely avoid but, at a minimum, lessens the above-described disadvantages of the prior art and is useful in particular for the production of nuclear, biological, and chemical warfare (NBC) protective materials, such as protective suits, protective gloves, protective footwear and other protective garments and also protective covers, sleeping bags and the like.
The present invention is further directed to providing an adsorption filter material which, as well as having good gas and water vapor perviousness, provides a protective function against chemical and biological noxiants and poisons, especially chemical and biological warfare agents. A certain degree of weight saving on the part of the adsorption filter material is desired too.
The present invention is further directed to providing an adsorption filter material, especially for use in protective materials, such as protective suits, protective gloves, protective footwear and other protective garments and also protective covers, sleeping bags and the like, that ensures a high wear comfort.
The present invention further provides protective materials, especially protective suits, protective gloves, protective footwear and other protective garments and also protective covers, sleeping bags and the like, produced using the adsorption filter material of the present invention or comprising the adsorption filter material of the present invention.
The present invention finally further provides for the use of the present invention's adsorption filter material for producing protective materials of any kind, such as protective suits, protective gloves, protective footwear and other protective garments and also protective covers, sleeping bags and the like, preferably for NBC deployment, not only for civilian but also for military applications.